From: "J. Bruce Fields" <bfields@fieldses.org>
To: lioupayphone <lioupayphone@gmail.com>
Cc: Steve Dickson <SteveD@redhat.com>, linux-nfs <linux-nfs@vger.kernel.org>
Subject: Re: Re: why there is a complex sync between /var/lib/nfs/etab in user-modeand export_table in kernel mode?
Date: Mon, 22 Dec 2008 12:14:53 -0500 [thread overview]
Message-ID: <20081222171453.GM4191@fieldses.org> (raw)
In-Reply-To: <200812192250226871692@gmail.com>
On Fri, Dec 19, 2008 at 10:50:27PM +0800, lioupayphone wrote:
> >I hope this helps...
> :-) thank you very much. i think your comments are very clear and very
> helpful for me. but i still think rpc.mountd is somewhat complex. we
> all know that a daemon in user-mode is likely to be killed. rpc.mountd
> is no exception. once rpc.mountd was killed, there are no chance for
> the export_table to be updated via upcall.
>
> It cannot be denied that putting the etab into kernel mode is wastful
> for memory. but i still think it is an easy and stable method.
Even with the export table in memory, rpc.mountd will still be needed
for ip-address lookup (e.g. if a filesystem is exported to *.umich.edu,
and the kernel gets an rpc from 141.211.133.1, then it needs to do an
upcall to determine whether the given ip address matches that wildcard).
However it's true that there might be advantages to having the export
table in-kernel.
--b.
prev parent reply other threads:[~2008-12-22 17:35 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-12-18 6:34 why there is a complex sync between /var/lib/nfs/etab in user-mode and export_table in kernel mode? lioupayphone
2008-12-18 15:51 ` Steve Dickson
2008-12-19 14:50 ` Re: why there is a complex sync between /var/lib/nfs/etab in user-modeand " lioupayphone
2008-12-22 17:14 ` J. Bruce Fields [this message]
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